The present invention relates generally to an improved liquid cooling system and more particularly, to an improved liquid cooling system for a snowmobile or other small vehicles.
Presently, many snowmobiles and other vehicles with relatively small internal combustion engines are air-cooled. The satisfactory performance of these vehicles with air-cooled systems depends largely on the volume of ambient air contacting the heat exchange elements. Some of these air-cooled systems have fans or other means for forcing the ambient air into contact with the heat exchange elements, but most rely upon movement of the vehicle to generate the necessary airflow. Although air-cooled systems with fans function quite satisfactorily, the provision of a fan or blower in a snowmobile or other small internal combustion engine vehicle is generally undesirable due primarily to the additional cost of the fan and the space needed to house such a fan. This latter factor is particularly pertinent in small vehicles such as snowmobiles, all-terrain vehicles, motorcycles, etc.
Most snowmobiles or other small vehicles having air-cooled systems without fans or other air forcing means function satisfactorily at higher speeds (in excess of 10-15 mph) since the air flow resulting from movement of machine at these speeds provides sufficient cooling of the engine. During idling, and at slow speeds (less than 10 mph), however, the air currents caused by movement of the machine are often insufficient, thus resulting in over heating of the engine.
Recently, several manufacturers have been using liquid cooling systems in snowmobiles and other small vehicles. In general these liquid cooling systems include a radiator element positioned generally vertically (perpendicular to the movement of the vehicle), a single air scoop for providing a flow of air to such radiator element, and an outlet duct for directing air from the radiator horizontally away from the machine. Although these machines, in some respects, are an improvement over the previous air-cooled machines, insufficient cooling problems are still encountered during idling of the vehicle and at relatively slow speeds. As with the air-cooled systems, these problems result from insufficient airflow over the radiator element. For the reasons discussed above, a real need exists in the art for an improved cooling system, and particularly a liquid cooling system, for a snowmobile or other small internal combustion engine vehicle to provide sufficient cooling of the engine during idling and at relatively low speeds.